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Two taps together can fill a tank completely in 3 13 minutes. The smallertap takes 3 minutes more than the bigger tap to fill the tank. Howmuch time does each tap take to fill the tank completely ?P.T.O |
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Answer» Let the volume of the cistern be V. Together two pipes take 3 1/13 mins = 40/13 Rate of both the pipes together = V/(40/13) Let pipes be A and B, Time taken by A = t mins , So rate = V/t Time taken by B = t+3 mins, So rate = V/(t+3) Combined rate = V/t + V/(t+3) We already know that combined rate = V/(40/13) Equating both , V/t + V/(t+3) = V/(40/13) 1/t + 1/(t+3) = 13/40 (t+3+t) / t(t+3) = 13/40 (2t + 3)/ (t^2+3t) = 13/40 80t + 120 = 13t^2 + 39t 13t^2 - 41t - 120 = 0 The quadratic equation yields two roots : 5 and -1.846 , since time cannot be negative Time taken by pipe A = 5 mins Time taken by pipe B = 5+3 = 8 mins Like my answer if you find it useful! |
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